Underreamer



June 9252,

,539,99 J. s; BROWN UNDERREAMER l Filed March 24 1922 4 sneetssneet 2 VyJ. 26, y

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earner JACOB S. BROWN, OF LOS ANGELES, CALFORNI, ASSGNOR BY DIRECT ANDMESNE ASSEGNMENTS, @F @NE-:HALF T WALTER F; EICHENHOFER, OF LOS ANGELES,

CALEFQRMI.

Unnnannarann.

Application filed March 24, 1922. Serial No. 546,356;

To aZZ 'whom it may concern;

Be it known that l, JACOB S. BROWN, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofQaliornia, have invented new and useful linprovementsin Underreamers, ofwhich the following is avspecica'tion. 4

My invention relates to underreamers for enlarging'the' bore 01' wellholes to permit the lowering of the casing, and a purpose orn myinvention is the provision of an underreamer having cutters of extremelydurable construction; adequate bearing surfaces to withstand the variousstrains to which the parts are subject in operation; eflicient andsimple means for maintaining the cutters in expanded position orunderreaming, and providing for their positive collapsing while beinginserted into or withdrawn from the well hole;V and means for allowingof the ready disassembling or removal of the cut# ters,

.Il will describe one form of underreamer' embodying my invention andwill then point out the novel features thereofl in claims,

ln the accompanying drawings,

Figure 1 is a view showing in rontelevation one form of underreamerembodying my invention: l

Figure 2 is a view showing the underreamer in side elevation.

Figure 3 -is a vertical longitudinal seotional view of the underreamershown in the preceding views with the cutters in contract- 'ed positionFigures d `and 5 are views showing in side elevation and top plan,respectively, one of the cutters comprised in the underreamer i :shownin the preceding views,

Figure 6 is a view similar` to Figure 3 showing the cutters in 'expandedposition.

Figure Z is a transverse sectional 'View taken onthe line 77 of Figure YFigure 8 is an enlarged detail view showing the inner side of theclosure disc shown Figure 7 together with the spring., Figure 9 is aview similar to Figure 8 showing the outer side of the disc and thelatter turned against the tension of the spring to align the discopening with respect to the stock openinga v Figure 9a is averticalsectional view showing in detail the stoet'` embodied in the underreamer'shown in the preceding views.

Figures 10 yand 11 are transverse sectional views taken on the lines10-10 and ,11-11 of Figure 9a.

Figure 12 is a bottom plan view of the stock shown in Figure 9a.

Similar reference charactersrefe-r to similar parts in `each of theseveral views.A

Referring specilically to the drawings, and particularly to Figure 9,the underreamer is shown as including a stock 01 body designatedvgenerally at S and provided with a longitudinal extending bore 15communicating atjits lower cnd with a bore 16 of' smaller diameter toprovide at the junction oi the two an annular shoulder 1T. The lowerportion of thestock is formed at diametrically opposed points withlongitudinal extending slipways 18 communicating at their upper endswith sockets 19 having inclined s urfaces20 which function as guides aswill be h'ereinafter'described. The wall separating the slipways 18 andthe bore 16 is slotted longitudinally vas indicated at 21 andy atdiamet-rically opposed points to com-- municate with the slipways. Asshown in Figures 9 and 12, the lower end o the stocli is recessed asindicated at- 22 to Jform a head 23 which constitutes the bottom of thebore 16. The head 23`is formed with a threaded bore 24 adapted for thereception of a screw. The side tacos of the head provide verticalshoulders. Referring now to Figures 3 and 6, the bore 15 of the stoclr-S is shown as receiving a rod 25 threaded at its upper end to receive anut 26 andbeneath which latter is arranged a washer or ring 27. lThelower end of therod is provided with a plunger 28 adapted for slidingmovement within the bore. '16. A coiled vexpansible spring 29 isarranged. within the bore 15 and in surrounding relation with respect tothe rod 25n 'This spring 29 is interposed between the washer 27 and awasherr() engaging with the shoulder 17,

thisarrangement causing the spring to normally urge the rod andconsequently the head 35 is formed which is adapted to work within thecorresponding socket 19. The

shanlV 34 is formed with flat sides andan the cutters are in expandedposition fas comp etel inner ed e which is inclined as indicated at 34`with its lower end extending inwardly to provide a thrust shoulder 34".Below the vshoulder 34 flat bearing surfaces 34c are formed onprojections at the junction of the shank and bit, these surfaces beingadapted to engage the shoulders on thehead 23 when shown in Figure 6.

For limiting the downward movement of the plunger 28 to allo'wof thecutters octhatits upper endis flush with the upper 'surface o the head23, the plunger can occup a position wherein the heads are removed fromthe sockets 19 thereby a lowing the removal of the cutters Kv from thestock.

.To maintain the plun er in this lowermost position wherein t e cutterscan be removed, I provide a rod or pin 37 having a handle 38 which, asclearly shown in Figure 7, is extended through suitable openings '4formed 'in' a'closuredisc 39, stock S, and the plunger 28, it beingunderstood that these `openings are in re istration only when clearlyshown in Fi the spring 29, itis necessary in order'to in-v spring the`Vplunger is in its owermo'st position. To prevent the passa e of oil,mud, or other foreign matter into t e stock through these openings, theclosure disc 39 is rotatably sustained within a recess formed in the'stock S by means of a screw 40. The opening 41 is normally out ofregistration with the stock opening so as to close the latter andprevent the passage of foreign matter into the stock.: The disc isretained lin this position by means of a spring 42 which, as clearlyshownvin Figure 8, is coiled intermediate its ends to embrace the hub ofthe ldisc while its ends are extended to engae shoulders 43 formed byrecessing the un er side ofthe disc. The tension of the is ,such as toallow the manual turning o the disc'to move the opening 41 intoregistration .with the stock openingv as `is The operation o fullyexpanded positionv under' the action of -,'sert the underreamer into thewellvcasing 1 to2-force the'plunger"28 downwardly to the position shownin Figure 3 in order that the cutters can be, moved to contractedposition.

. described.

i the underreamery is *asl follows: As the cutters K normally occupy Theattendant ulls down on cutters K and the plunger is eld in this loweredposition by employin `the rod or` pin 37 as has been n movin the cuttersto contracted position, the ugs,` 32 engage the plunger 28 so as 'tomoveit and consequently the cutters downwardly u til the bearingsurfaces 34-are disengaged rom the head 23 thereby allowing an inwardmovement ofthe cutters until the surfaces 34 contact with each other asis clearly shown in Figure 3. In this position of the cutters the heads35am not completely withdrawn from the sockets 19 so that when downwardpressure upon thev plunger is relieved, the spring can operate inelevating thecuttersto expanded position, it. being understood that theends of the heads en e the inclined surfaces 20 so as to be gu; backinto. the sockets1`9. i.

When the cutters are in contracted position the undereamer can bereadily inserted in to the well casin and this o ration having beencompleter/I the pin 37 is withdrawn but as the well 'casing retains thecutters in contracted ositiont e springnow fails to function. fterpassing the underreamer downwardly through the well casing, the cuttersautomatica ly .move to expanded position under the action of the spring29 when the cutters have passed below the wll -A casin v During v themovement of the cutters om contracted to expanded position, the thrustshoulders 34 wipe thelower edges: of the head 23 thereby eecting ythegradual expansion of the cutters as the move upward] In the completelyexpan y ed position o thecutters, the bearing surfaces 34 contact withthe opposite sides of the head 23 and cooperate with the heads 35 andthe'sockets 19 in effectively bracing thecutters inI fully expandedvosition so 4that the underreamer is now rea y for operation. t l

Although I have hereinrshown and delosv `scribed only one formof'underreamer emthe slipways, a plunger movable in the stock and havingan opemnlg formed therein, cutters mounted inthe s ipways and includingShanks andl heads formed on the lShanks adapted to fit in` said-sockets,lugs formed on the 'Shanks and engaging within the openin forme 'on theshanksandengagable with said head to effect expansionof the cutters`when the plunger is moved in one" direction,

of said plunger, .thrust shoulders and means for 'urging the plunger toa defi-.

2,'An underreamer comprising a stock having slipways'formed therein andsockets at one end of the slipways, .a plunger movable in the -stockbetween the slipwaysand .sockets to occupy two extreme positions, saidplunger being't'orined with an opening, a

head formed in the stock between said sli p ways, cutters mounted in theslipways, heads formed on the cutters adapted to tit within saidsockets, lugs formed on the cutters en-' gaging within the opening ofsaid plunger, thrust shoulders and bearing surfaces ornr ed on thecutters and adapted. to engage said head for moving the cutters toexpanded or contracted position upon movement of said plunger, means torurging the plunger to one extreme position in which the heads aredisposed within saidA sockets and the bearing surfaces'a're incontactwith said head, and an adjustable member mounted in said head fordefining the other extreme position of said plunger.

3. An underreamer comprising a stock, cutters mounted 'in the stock tooccupy. expanded and contracted positions, a plunger operativelyconnected. to the cutters and movable in the stock to occupy oneposition in which the cutters are expanded and another position in whichthe cutters are'contracted,said stock and plunger being formed withopeningsv adapted to register when the plunger is in the secondmentioned posltion, a closure plate movablevto control the open- -ing ofsaid stock and normally urged to Aa position in which the stock openino'is closed, and a tool adapted to be inserte-d through said plate and theopenings of said stock and plunger for retaining the plunger in thesecond mentioned position.

4. An underreamer comprising a stock, cutters mountedin the stock tooccupy expanded 4and contracted positions, a plunger operativelyconnected ,to the cutters and movable in the stock to occupy on`position in which the cutters are expanded, a second position in whichthel cutters arecontracted, and a-third position' in which the' cutterscan be renioved from thefstock and plunger,

adjustable means for defining the last-two .positions of the plunger,and means for ving the plunger to the firstmentioned position.

5. An underreamer comprising a stock having slipways formed therein, aplunger movable in the stock between the slipways to occupy two extremevpositions, a head formed in the stock between said slipways, cuttersmounted. in the slipways and engagable by said plunger so as to be movedto expanded or contracted position, means for urging the plunger to o'neextreme position in which said cutters occupy expanded position, and anadjustable member mounted in said head for defining the otherl extreme,l

position of said plunger.

6. An nnderreamer Icomprising astock 'having slipways formed therein, aplunger movable in the stock between the slipways'l to occupy twoextrem'e positions, a head formed in the stock betweenjsaid slipways,

cutters mounted in the,y slipways and engagable by said plunger so as tobe moved to expanded or contracte' urging the plunger tol one extremeposition position, means for y in which said cutters dccupy expandedosition, and a screw plugj mounted in said ead for ,defining the othei`extreme positionl of said plunger. y 3

7. An underrezmierl comprising a stock, having slipways formedthercinwhich communicate with the lower end of the stock,

the lower end face of the stock being recessed, .a head formed in thestock adjacent to and in thev recesses andhaving side shoulders betweenthe lower ends ofthe slipways, a plungermov-able in the stock betweenthe slipways and above -the head, a screw mounteduvertically throughthe' head to engage the plunger and adjustably limit the 1nove ment ofthe plunger toward the head, and cutters mounted in the slipways andengagable by the plunger, ksaid cutters being formed with extensionshavinf side faces to engage the shoulders for -defini'ng the expandedposition 'of the cutters.Y

In testimony whereof I have signed my name to this specification.

JAooB s. BROWN.

